Taming Full Batten Mains

One of the great ironies of sailing is that as hard as it can be to get your mainsail up, it can often be just as hard to get it back down. This goes double when tucking in a reef with a slab-reefing system—one reason why so many sailors are willing to sacrifice sailing performance for the sake of in-boom or in-mast furling.

These problems are magnified when flying a full-batten main, or even one with a single full batten near the head. Granted, full-length battens provide a significant performance boost and, when flown with lazyjacks, make a sail easier to douse because it doesn’t spill onto the deck. However, they can create huge problems by causing conventional slides or slugs to catch as they run up or down the mast.

The reason for this is that full battens both sag and twist as soon as you ease the halyard. This, in turn, imparts torque to the corresponding slide or slug, causing it to jam up in the mast track. The battens in full-batten mains are also slightly longer than their batten pockets, in order to force an aerodynamic shape into the sail. This creates compression between the luff and leech and against the trailing surface of the mast, creating yet more friction. The result is not only annoying, but can quickly escalate into an emergency under the right conditions—say, in a sudden gale or on the approach to a tight anchorage.

To eliminate this friction, manufacturers have developed a number of different luff attachment systems. Some incorporate ball bearings, others employ low-friction polymers; some require special mast tracks, while others make use of a mast track’s existing luff groove. In every case, the goal is the same.

To eliminate the twisting problem in particular, the luff slides attached to batten pockets in these systems include some kind of a flexible linkage. Typically, this is a universal joint, much like a miniature version of the gooseneck on a boom. One slight variation is the joint found in Dutchman track and mast-car systems, which combines webbing and a ball joint.

These universal linkages typically feature a threaded stud compatible with batten receptacles from a number of different manufacturers. This is important because, as Harken’s Syd Millman explains, different sailmakers often prefer to work with different receptacles. A threaded attachment also allows you to make adjustments to compensate for minor differences in the distance between the sail and the mast.

While intermediate slides between batten pockets don’t include these same sophisticated linkages, a well-made slide will still allow for some play in the luff. In many cases, this linkage is made using a short length of webbing or a small shackle. Schaefer Marine also offers what it calls its Magic Shackle, which can be used on both full-batten and conventional mains.

Seldén is somewhat unique in that it makes its intermediate car connections with a detachable swivel, which can then be attached to a luff cringle with webbing. These swivels are easily detached from their cars, so the sail can be unbent while leaving the cars on the mast. Similarly, Ronstan incorporates a quick-release feature that allows the webbing and mechanical batten receptacle linkages to be quickly removed, so the cars can be left on the mast whenever the sail is removed.

As for the cars or slides themselves, there are a number of different systems on the market incorporating ball bearings, low-friction polymers or a combination of the two. Ronstan’s CB (captive ball) cars, for example, include a pair of low-friction slide rods, which contact the sides of the track while two sets of captive Torlon ball bearings contact the track’s face. According to Ronstan’s Alan Prussia, this “top” ball bearing configuration works well at minimizing fore-and-aft compression loads. Because the ball bearings are captive, the cars can be easily removed from the track.

Not surprisingly, given its long history using ball bearings to reduce friction aboard sailboats, Harken’s Battcar line includes a number of captive ball car models as well, which can be installed or removed from a track without having to worry about chasing down a bunch of loose ball bearings. The Harken line also includes the option of low-friction slides, which according to Harken’s Millman, can be used on smaller rigs with smaller loads or as intermediates on larger rigs to help reduce cost and weight aloft. “They all work on the same track,” Millman explains. “Of course, if you want the Cadillac version, you can always go with all ball bearings.”

Dutchman Sail Hardware—known for its unique mainsail flaking system—manufactures a range of luff cars that employ a combination of ball bearings and small wheels. According to Dutchman’s Martin van Breems, the arrangement works well because the wheels contact that mast, not the ball bearings, which helps keep the latter free of grit. Of course, these slides and cars all need something to run on, and here again manufactures offer a number of options, including everything from external tracks to dedicated mast extrusions.

Seldén, for example, sells a range of extrusions specifically configured for use with its MDS (multi-directional support) line of batten cars. The bulk of each car, which includes two pairs of wheels to absorb both fore-and-aft and side loads, is contained within the extrusion, which supports the car in all directions. In addition to providing a secure low-friction interface, the fact that there is no need to install an additional track helps reduce weight aloft.

Another no-track option is Ronstan’s Ballslide T car, which uses the existing luff slot in a conventional mast. Each Ballside T includes two sets of captive balls, which contact the outside of the mast on either side of the slot, and a pair of internal slugs to hold the car in place.

According to Ronstan’s Prussia, in addition to working with conventional full-batten mains, a single Ballslide T car can be used on a main with a single full batten at the top. This includes sails with boltropes. “On any boat with a full-length batten, the Ballslide T can make a big difference,” he says.

Dutchman roller cars are also designed for use with a conventional mast extrusion—an economical solution that saves modifying a mast. However, van Breems warns that sailors with older boats shouldn’t expect miracles. If your mast is anodized aluminum and the luff slot is in good shape, the system may work properly. But if your spar is pitted and corroded, bearing cars will also likely have problems making their way up and down it.

In terms of tracks, there are two basic types: aluminum tracks installed in sections and low-friction polymer tracks that can be installed in one long piece. Polymer tracks can only be used with slides, because ball bearings would distort the material over time. Aluminum tracks can be used with both ball bearings and slides.

Tides Marine’s Track and Slide system represents an excellent example of the polymer approach. Manufactured from Black Ultra-high-molecular-weight (UHMW) polyethylene, the tracks are machined in a female “C” shape, which holds the sail’s low-friction stainless steel slides. The forward surface of the tracks is machined to slide into a conventional luff slot. Thanks to their flexibility, the tracks are available in lengths up to 65 feet (they arrive coiled in a large flat box), which allows for a seamless track with no joints. The track can even be installed with the mast still stepped.

Dutchman Sail Hardware also manufactures its tracks from UHMW polyethylene, but machines them in a “T” shape so the slides and cars ride on the outside. According to van Breems, this further reduces weight aloft because the “T” profile is especially compact. Tracks are available in 55 foot lengths and—as with the Tides Marine track—require almost no mechanical fasteners, making it ideal for retrofits. According to both van Breems and Tides Marine’s Jeff Strong, the polymer track and slide approach offers the added benefit of simplicity. “Fewer moving parts means less to go wrong,” Strong says.

In contrast, aluminum tracks all require a set of slugs set inside an extrusion’s existing luff slot that are attached to the track itself with screws that hold the latter against the trailing edge of the mast. In some cases, professional riggers will forego the slugs, and use screws and drilled/tapped holes. But this is beyond the ability of most DIYers. Although they may look complicated, slug-and-screw installations are fairly straightforward, well within the ability of a handy sailor. With carbon spars, tracks are attached with adhesives, with only a few screws to hold the track in place while the adhesive sets.

Of course, aluminum tracks cannot be coiled, so they ship in sections. Harken, for example, ships its “T” profiled track in 7-foot sections, while Ronstan ships in lengths ranging up to 18 feet. Schaefer Marine sells tracks sections featuring a “C” configuration that can be used with a variety of different aluminum and nylon slides. Correctly installed, aluminum tracks are extremely robust, capable of handling the loads on everything from a smaller performance-cruiser to a megayacht.

Harken has also developed a nifty product it calls its Switch Track. Somewhat reminiscent of railroad switches, this track allows you to alternate cars and slides from one side to the other, thereby reducing the “stack height” as the luff of a sail gathers above its tack. A trysail version allows you to bend on the sail at deck level, where it can then be stored out of the way until needed. When the wind pipes up, simply lash the main onto the boom and hoist the trysail off its side track onto the one used for the main. No more having to switch out sails in a gathering storm.